The TRS-80 has TROFF and TRON! https://www.youtube.com/watch?v=IQoL_qpYbW0 https://www.youtube.com/watch?v=IQoL_qpYbW0 More useful but not quite as magical as

The TRS-80 has TROFF and TRON! https://www.youtube.com/watch?v=IQoL_qpYbW0 https://www.youtube.com/watch?v=IQoL_qpYbW0 More useful but not quite as magical as DECSYSTEM 10 and DECSYSTEM 20 BASIC's "LISTREVERSE" command! https://web.archive.org/web/20210713130832/https://imgur.com/a/Bt40M https://web.archive.org/web/20210713130832/https://imgur.com... Chalk one up for DEC and BASIC. What other programming languages support that feature, huh? Now all you need is a COMEFROM and COMESUB and RUNREVERSE (or NUR) statements, and you can write reversible BASIC programs! https://en.wikipedia.org/wiki/Reversible_computing https://en.wikipedia.org/wiki/Reversible_computing https://en.wikipedia.org/wiki/Counter-Clock_World https://en.wikipedia.org/wiki/Counter-Clock_World DECSYSTEM 20 BASIC User's Guide: LISTREVERSE command LISTREVERSE LISTNHREVERSE LISTREVERSE and LISTNHREVERSE print the contents of the user's memory area in order of descending line numbers. LISTREVERSE precedes the output with a heading, LISTNHREVERSE eliminates the heading. LISTREVERSE EQUIV 10:53 13-NOV-75 40 END 35 PRINT "THE EQUIVALENT CURRENT IS",I, " AMPERES" 25 I=E1/R 10 INPUT R 5 INPUT E1 READY http://bitsavers.org/www.computer.museum.uq.edu.au/pdf/DEC-10-XBRCA-A-D%20DECsystem10%20Basic%20Language%20Reference%20Card%20(Version%2017B).pdf http://bitsavers.org/www.computer.museum.uq.edu.au/pdf/DEC-1... http://bitsavers.org/www.computer.museum.uq.edu.au/pdf/DEC-20-LBMAA-A-D%20BASIC%20User's%20Guide.pdf http://bitsavers.org/www.computer.museum.uq.edu.au/pdf/DEC-2... Emacs should have an edit-reverse-mode!